A few days ago, we received a private message from a fan called David Rogers who discovered a Sega Mega Drive/Genesis ROM which appears to be prototype of Fantastic Dizzy.
He discovered the ROM on the server of the 'English Amiga Board' in a collection of other Sega ROMs.

Also enclosed in the zip are descriptions and screenshots of all the differences and unfinished sections that are on this prototype.
There's a lot to go through on this thread alone but what I can point out.
- No Audio
- Dizzy missing from Codies screen
- No title and Intro
- Score doesn't work
- Unlimited Lives
- Palette changes on some sections
- Early graphics including a bigger Pogie
- The extra life Puzzle is a lot different.